#include <stdio.h>

int main(int argc, char *argv[]) {
    
    int k,count=1;
    scanf("%d", &k);
    double sum = 1, div = 2;

    while (k>=sum)
    {
        sum += 1 / div;
        div++;
        count++;
    }

    printf("%d", count);


    return 0;
}